1. Field of the Invention
The present invention relates to a method and an apparatus for making shaped and laminate articles, and more particularly, to an apparatus that recovers excess material or flash for recycling as a part of the shaping and laminating process.
2. Background of the Invention
Rotary dies and methods of using such dies are conventionally used in this art to produce shaped and laminated articles of continuous lengths or discrete shapes. Examples of such articles include seals and gaskets, expandable articles for automotive uses, diapers, edible items such as cereal, printed matter such as labels and cardboard boxes, and other sheet goods.
U.S. Pat. Nos. 4,427,481; 5,266,133; 5,373,027; 5,678,826; 5,040,803; 4,874,650; and EP 0 730 998B1 disclose methods and apparatus that fabricate automotive expandable sealants. U.S. Pat. Nos. 5,411,390; 5,417,132; and 5,515,757 illustrate examples of conventional shaping and laminating methods and apparatus, the disclosure of each of which is hereby incorporated by reference. While conventional methods and apparatus are useful for making articles, there is a need in the art for methods and apparatus that reduce material cost without compromising the efficiency of the apparatus or the quality of the produced articles.
Conventional shaping and lamination apparatus typically do not recycle unused raw material as a part of the manufacturing process. Often the raw material is shaped and formed into a final product and cut-away portions of material, known as flash, are collected as an afterthought. The typical apparatus do not recover the flash in a systematic manner that facilitates recycling. Thus, much of the unused raw material is thrown away and wasted.
Laminate products present additional obstacles to recycling. Even if an apparatus recovers the flash from a laminate product, often the multiple layers of varying materials are inseparable and incompatible with recycling operations.
Thus, if the apparatus collects the laminate flash at the end of the manufacturing process, the flash cannot be recycled.
In addition to inadequate flash removal, the rotary die apparatus known in the art present three other significant drawbacks. First, conventional apparatus typically use individual rotary processing stations. Therefore, when the machines must be re-tooled to accommodate new products, the single individual station must be taken out of service for extended periods of time. The prior art apparatus do not provide means to quickly change shaping or laminating functions without curtailing production.
Second, conventional rotary die apparatus regulate web tension with nip or pinch rollers. In conveying the web material, these rollers must contact the top of the web material. Often, the pinching action of these rollers damages the web material and diminishes the quality of the final product. The prior art apparatus do not provide means to consistently convey the web material without excessive, deleterious handling.
Finally, in facilitating flash removal, conventional rotary die apparatus spray lubricant on the entire web material and rotary die. Such a method uses excessive amounts of lubricant and degrades the quality of the web material because of over-saturation. The prior art apparatus do not provide means to apply minimal amounts of lubricant to the specific locations at which lubrication is needed for effective flash removal.
For the foregoing reasons, there remains a need for an apparatus that cuts and segregates flash from a web material before the material is laminated to another web material. The apparatus should effectively remove flash using careful handling and lubrication means to avoid degrading the quality of the final product. Further, the apparatus should provide means to easily and quickly change the shaping or lamination functions without hindering production.
The present invention provides a method and apparatus for die cutting and making shaped and laminated articles in a process that efficiently recovers unused recyclable flash material without adversely impacting production speed or quality. The present invention reduces material waste in the shaping of a web of material or the laminating of at least two films, layers or web stock and also permits changing or modifying the product being produced without stopping production.
To shape and laminate product material while continuously separating flash, the apparatus uses a novel, multi-station arrangement of stepped anvil rollers, regular anvil rollers, vacuum conveyor belts, and lubrication systems.
For the shaping configuration, a web material is fed between an anvil roller and rotary die. Depending on the number of layers in the web and the desired cut, the anvil roller is either stepped to produce a through-cut or is regular to produce a kiss-cut. A kiss-cut is a cut through part, but not all of a multi-layered article, wherein the cutting die gently or lightly cuts the web material without cutting the liner or substrate. After the die and anvil roller cut the web, a flash removal mechanism, e.g., conveyor belt, vacuum nozzle, or web rewind, removes the web flash and delivers the flash to a recycling operation. To ease removal of the flash, a lubrication system applies lubricant directly to the blades of the rotary die before the die contacts the web material.
For the lamination configuration, two anvil rollers are positioned adjacent to and on opposite sides of a rotary die. The two anvil rollers are referred to hereinafter as the first anvil roller and second anvil roller. This die and anvil roller configuration enables the feeding of two web materials. In the horizontal plane, a primary web material is fed between the rotary die and second anvil roller. From above the apparatus, a secondary web material, e.g., a film, is fed between the rotary die and first anvil roller.
The first anvil roller and rotary die cut the secondary web material into two portions, secondary web flash and secondary web product, before the secondary web product contacts the primary web material. Thus, the secondary web flash is removed before the materials are laminated and no longer suitable for recycling. The secondary web product meets the primary web material as both materials enter between the rotary die and second anvil roller. As the materials meet, they are laminated and the primary web material is cut into two portions: primary web flash and primary web product. The primary web flash is removed for recycling and the primary web product continues on a horizontal conveyor for further processing or packaging.
Like the shaping configuration, in the lamination configuration, a lubricant system improves flash removal by applying lubricant directly to the blades of the rotary die before the die contacts the secondary web material or primary web material. Additionally, the first and second anvil rollers can be either stepped or regular to produce the desired cut and the flash removal mechanism can be tailored to meet recycling requirements, e.g., conveyed, vacuumed, or rewound.
A further embodiment of the present invention incorporates the above-described shaping and lamination configurations in a multi-station system in which successive die and anvil roller assemblies are positioned along a production line. The die and anvil roller assemblies are mounted on lifting mechanisms, e.g., pneumatic cylinders, that allow the assemblies to be raised and taken out of service. When raised, the rotary die does not contact the primary web material and therefore does not shape or laminate. In this manner, the shaping and lamination functions can be stopped and started while the web materials are continuously fed.
Accordingly, it is an object of the present invention to provide a means for cutting a web material and removing flash before the web material contacts another web material in a lamination process.
It is another object of the present invention to deliver a web material to a rotary die without contacting or handling the top of the web material so as to reduce the possibility of damaging the web material.
It is another object of the present invention to enable quick changes between shaping and lamination functions in a die cutting apparatus.
It is another object of the present invention to provide a lubrication system for a die cutting apparatus that minimizes wasted lubricant and reduces degradation of the web material from over-saturation.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings and the attached claims.